I'm using a slightly modified code from perlre to extract the parameters to a method call in VB, that is , to match the contents of properly nested braces, skipping the braces found in VB-style string constants and I found something strange. It seems I cannot use my, for the $braces variable. Try the following code with and without the "my": 

my $braces = qr{
           \(
           (?:
              (?> [^\(\)"]+ )    # Non-parens without backtracking
            |
              (?> "[^"]*")+        # skip string constants
            |
              (??{ $braces })     # Group with matching parens
           )*
           \)
        }x;
my $Braces = qr{\(((?:[^\(\)"]+|"[^"]*")*(?:$braces(?:[^\(\)"]+|"[^"]*
+")*)*)\)};

my $str = 'foo( FieldName, trim(CStr(Request.Form(FieldName))), Countr
+yId )';

$str =~ $Braces and print "YES: $1\n" or print "NO!\n";

[download]
I get 
YES: CStr(Request.Form(FieldName))

[download]
with the "my" and 
YES:  FieldName, trim(CStr(Request.Form(FieldName))), CountryId

[download]
without "my" with 
This is perl, v5.8.0 built for MSWin32-x86-multi-thread
(with 1 registered patch, see perl -V for more detail)

Copyright 1987-2002, Larry Wall

Binary build 805 provided by ActiveState Corp. http://www.ActiveState.
+com
Built 18:08:02 Feb  4 2003

[download]
running under Win2k Server SP4

Is this a known bug, my misunderstanding, something that did not bite anyone yet, ...?

Thanks, Jenda
We'd like to help you learn to help yourself
Look around you, all you see are sympathetic eyes
Stroll around the grounds until you feel at home
   -- P. Simon in Mrs. Robinson

In reply to (??{...}) in regexps and lexicals by Jenda

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